Replacing the CAT on a 2003 Focus

My Focus has been getting bad gas mileage lately, so I used a code reader. It displayed a P420 code which is a convertor problem. I have a parts car, so I took the convertor off it, and swapped them out. Hopefully this will cure the problem. I also had to do some repair welding on the CAT rear flange, as it was badly eaten away and wouldn't retain the bolts.

[@twocvbloke]

Remember, if you find the cat on your car is meowing, that's the wrong cat... :P

[@ChargerMiles007]

LOL, yes, no doubt!

[@samcardon4676]

Maybe it needs the good old "Italian" tune up to blow out the cob webs?

[@artemdevo3161]

why not break a hole right through the cat, opening it up, and putting a defouler on the downstream sensor to fool the ECM?

[@ChargerMiles007]

That could be done, though I prefer to at least attempt to keep things smog legal. Plus when you smash a hole through the catalyst, you have no resale value for the CAT.

[@douro20]

That engine is pretty messy...sure it's not leaking oil?

[@ChargerMiles007]

Yes, it is leaking oil, unfortunately it seems to be pretty hard to make it not leak oil. I replaced the cam cover gasket, but it still wants to leak. I even modified the PCV hose so that it can't collapse under vacuum, bit it still insists on leaking oil out of the cam cover at the front. It doesn't use much oil though, as I hardly ever have to add any to it.

[@simon35795]

If its Burns Oil it Will fuck up the cat